1. Field of the Invention
The present invention concerns the utilization of addition polymerization, e.g., vinyl polymerization, in diagnostic test compositions for detecting and measuring an analyte possessing biologic activity and in methods for detecting and measuring an analyte possessing biologic activity.
2. Background Information
Modern diagnostic tests for trace amount of analyte possessing biologic activity, such as those encountered in clinical laboratory medicine often employ immunologic (i.e., antigen-antibody) reactions. More recently the use of probes for the assay of nucleic acids has entered the realm of clinical and research laboratories. These highly specific reactions are detected by means of a label or tag, attached to one of the components, that is either chromophoric, fluorescent, radioactive, chemiluminescent or an enzyme that can generate such signals. Chromophore labels for detection of trace analytes are of historic and academic interest only because of their low sensitivity. Color detection methods are capable of detecting no fewer than 10.sup.18 to 10.sup.15 analyte molecules per milliliter, while radioisotope detection methods can approach a detection sensitivity in the range of 10.sup.8 to 10.sup.7 analyte molecules per milliliter.
Fluorescent, chemiluminescent and enzymatic methods as characterized by relative-specific-activities can be more sensitive than radioisotope methods by at least two or more magnitudes. These are goals, however, and not achievements. Continued increases in sensitivity are reported as these methods are refined, but no magnitude jumps are anticipated.
Prior to the present invention, no one proposed the coupling of an extraneous non-catalytic substance with a catalyst component of vinyl polymerization. If the extraneous substance is a highly specific ligand for a target analyte of interest, then the production of detectable polymer can indicate the presence and site of the analyte. This linkage provides the basis of a unique detection system. The present invention when applied to analytes of biologic interest provides a diagnostic technique useful in the fields of medicine and agriculture.